Trouble Brewing at the Bottom of the Bay

Peter Fear is quoted in The Age on channel deepening

By Melissa Fyfe.
As printed in The Age, December 6, 2003.

The Melbourne Cricket Ground comes in handy
when describing big things - it is a particular
quirk of the Victorian vernacular. Hugeness is
instantly conveyed: enough people to fill the MCG,
enough water, waste or empty beer cans.

And so it is with the Port Phillip Bay
channel-deepening project. It has been said,
and no one remembers now by whom, that the sand
and sediment the Port of Melbourne Corporation
wants to scour from the bay's bottom will be
enough to twice fill the MCG to the top of the
Great Southern Stand, if it went all the way around.

Someone else has said the spoil from deepening
Melbourne's shipping channel would fill Nauru House
up to 40 times. The actual amount, for the record,
is 30 million cubic metres for the deepening, and
another 10 million to maintain the channel over
the next 30 years. "It is a vast amount," says
John Arup, the consultant in charge of the Port
of Melbourne's $12.5 million environmental effects
statement.

The project is a widely misunderstood venture
that has failed to register with most lovers and
residents of Port Phillip Bay: four people showed
up to a "stakeholder-specific meeting" in Rosebud
last Saturday, and seven turned up for a similar
St Kilda meeting on Wednesday. But the stakes are
high for both the bay and the Victorian economy.
Allowing bigger ships into the bay, says industry,
would mean more jobs and lower freight costs,
therefore cheaper exports and imports for consumers.

On the flipside, the environmental risks
include everything from potential harm to St
Kilda's penguin colony, destruction of the marine
environment at the heads, and the finely balanced
water quality of the bay itself.

Melbourne is Australia's biggest container port,
but it has one big problem: its shipping channel
is shallow. The monster ships that crawl up the bay
and into the docks are gradually becoming the
minnows of the international shipping fleet -
outpaced by deeper, wider and generally bigger
agents of global trade.

Already this affects businesses that rely on
the port, through which 82 per cent of Victoria's
imports and exports are moved. In the past six months,
32 per cent of ships came in with less than 80 per
cent capacity. If the ships were fuller and, therefore,
heavier, they would hit the sea bed.

The big ships get rid of some of their load
before hitting Melbourne, says Rose Elphick,
the acting head of the Victorian Sea Freight
Industry Council. They may drop off containers
(some with perishable goods) in Singapore or at
another Australian port and the extra cost of
getting the goods to their destination is paid
by the importer or exporter, and eventually the
consumer. If this situation continues, Elphick
and the Victorian Employers Chamber of Commerce
and Industry say, Melbourne will gradually lose
business and jobs to more competitive, deep-water
ports such as Brisbane. In a $400 million project,
the Port of Melbourne wants to deepen the channel
in four places so that ships with 14-metre draughts
can get into the bay. Elphick says the efficiencies
of fully laden ships could mean a saving of $30
to $40 for each container of goods.

University of Melbourne professor of economics
John Freebairn says deepening the channel will be
a cost-effective way of lowering freight costs. But
the environmental costs must be factored in, he says.
"You and I have to make a decision: do we want to
find it more expensive to export and import and leave
the bay untouched, or are we going to lower the cost
of freight and accept the potential changes to the
environmental services offered to us by Port
Phillip Bay?"

So far, the big-ticket environmental concern
has been the fear that more water will come into
the bay, causing flooding and beach erosion. This
fear stems from the bay's particular geography.
The bay's mouth between Point Lonsdale and Point
Nepean is a narrow gate that controls the flow of
water from Bass Strait. Once ocean water gets
through the heads, it stays around for about
a year.

The Port of Melbourne plans to widen the heads,
removing 400,000 cubic metres of rock. The port
says the affected area will be small, but the
idea of widening the heads and possibly lifting
the bay's water level has environmentalist
Len Warfe almost beside himself.

"Any increase in water level will cause more
coastal erosion and flooding in low-lying areas;
there's no doubt about that," says the Dromana
resident and senior vice-president of the Port
Phillip Conservation Council Inc. "Combined with
the accepted greenhouse sea level rise, there's
no way you should be artificially increasing the
sea level to let bigger ships in."

The potential impact on bay levels is being
studied by oceanographer Dr David Provis, who has
16 years' experience of the bay's hydrology and
is one of around 50 specialists working on the
environmental effects statement. The first thing
he wants bayside dwellers to know is that their
lounge rooms will not be flooded. In fact, his
modelling shows the project will have "no impact
on coastal processes".

Having said that, his computer models reveal
a slight impact on the bay's tides. Looking at
tides over one month, 1 per cent will be more
than eight millimetres higher but all will be
less than one centimetre.

His modelling on the bay's sea level found
no extra areas would be wetted and no change in
the frequency of inundation of any piece of
coastline. Other modelling revealed that any
change to the heads would have no impact on
storm surges. The bay's wave patterns would
be unaffected.

Scientific experts who know the bay say
their biggest worry is the bay's unique and
delicate ecosystem, which controls its water
quality. In 1992, Melbourne Water commissioned
the CSIRO to do a $12-million, four-year study
of the bay, the biggest ever. One of its findings
was that the bay's water quality was actually
very good. Bugs and animals on its floor process
nutrients and keep the bay from turning into an
algal soup.

The study recommended that any disturbance
to the bay's bottom be minimised. "The science
was categorical on that," said the man who led
the study, CSIRO research fellow Graham Harris.
"The ecology at the bottom of the bay preserves
the values that the community cares about."

The key risk is not the deepening of the
channel itself, but the disposal of the spoil.
A small amount of the 40 million cubic metres may
go to building an environmental island or beach
restoration but most of it will be dumped on the
bay floor across an area of 1497 hectares.

"The placement of material would smother
anything that is there," says consultant John
Arup, the EES manager. This includes the
aforementioned bugs. It could have a food-chain
domino effect that affects everything from
dolphins to fish to penguins.

Another environmental storm is brewing at
the heads. Rock must be removed at the top of
beautiful canyons which Peter Fear, the owner
of Dive Victoria, says are just as ecologically
important as nearby marine parks.

Arup says the main environmental concern is
rock falling into the canyons. The Port of
Melbourne is looking at using a dredger that breaks
and then sucks the rock up. But the dredging
operation is particularly difficult because of
the strong currents and dynamic activity at the
heads.

The other concern is that explosives may
be needed, and this could affect the nearby
marine ecology as well as fish, seals, dolphins
and penguins.

The deepening of the south part of the channel
- which runs parallel to Portsea through to McCrae
- also has potential environmental and tourism
impacts. This area is important for fish larvae,
birds, sea grasses and shallow reefs. It also
has some very fine sand that, when dredged
(by a ship that sucks it up from the bottom)
may suspend itself in the water column and
create a plume, says Arup.

Arup says the dredging technique must be
improved because the risk is that a plume will
smother important sea grasses and reefs, reduce
sunlight and impact on the biodiversity. Maintenance
dredging created a large milky plume last summer -
to the outrage of divers, fishers and dolphin
tour operators.

In this same area, off the coast from Rosebud
and Blairgowrie, the Port of Melbourne has
floated the idea of building an environmental
island. The island would take a few million cubic
metres of the spoil and hopefully create a habitat
for birds.

The island is looking like a wobbly idea
because the EES experts admit it will be
difficult to make the sand stay where it is.
The last thing they want is it washing back
into the channel.

Moving further north, there is the logistical
concern of having to relocate one of the city's
main sewer lines, but the main environmental
risk is the contamination of the spoil near
the Yarra.

Tests have shown that the sediments are
polluted with industry, agriculture and storm
water chemicals, including arsenic, lead and
zinc. The key concerns, says Arup, are the
impacts of putting this onto another area,
and that it may contain marine pests.

Len Warfe questions whether the deepening
is necessary at all. The Port Phillip
Conservation Council believes Melbourne
should instead rely on rail for freight
(an idea dismissed as uneconomical and slow
by John Freebairn).

The Port of Melbourne has just released
its Key Features report, which outlines the
environmental issues. The project's
communications manager, Lisa Faldon, said
in March-April next year the port would
release another report that would outline
how it proposed to deepen the channel in
"a way that is environmentally responsible".

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